CN114105943A

CN114105943A - 3-substituted thioxanthone compound, preparation method thereof and application of photopolymerization system

Info

Publication number: CN114105943A
Application number: CN202010912443.3A
Authority: CN
Inventors: 金佳路; 邓伟; 罗子皓
Original assignee: Shenzhen Youwei Technology Holding Co ltd
Current assignee: Shenzhen Youwei Technology Holding Co ltd
Priority date: 2020-09-01
Filing date: 2020-09-01
Publication date: 2022-03-01

Abstract

The invention relates to the field of organic functional new material chemicals, and discloses a novel 3-substituted thioxanthone new-structure compound, a preparation method thereof, a radiation curing formula material system containing the compound and application thereof for the first time. These thioxanthone species are important photoinitiators for photopolymerization of ethylenically unsaturated systems as key fine chemicals.

Description

3-substituted thioxanthone compound, preparation method thereof and application of photopolymerization system

[ technical field ] A method for producing a semiconductor device

The invention relates to the field of organic functional new material chemicals, and discloses a novel 3-substituted thioxanthone new-structure compound, a preparation method thereof, a radiation curing formula material system containing the compound and application thereof for the first time. These thioxanthone substances are important photoinitiators (Photo-initiators) key fine chemicals for photopolymerization processes of ethylenically unsaturated systems.

[ background of the invention ]

Some thioxanthone compounds are known to be widely used photoinitiator compounds and/or photosensitizer (sensizer) compounds due to their excellent broad absorption properties of ultraviolet and visible light, and representative products are, for example, commercially available brands ITX or DETX, whose corresponding chemical structural features are 2-or 4-isopropyl substituted thioxanthone, and 2-and 4-ethyl substituted thioxanthone, respectively.

To date, 3-substituted thioxanthone-type compounds have not been reported in the literature and have never been used as photoinitiators. This is a new class of compounds with novel structures and is predicted by theory to possess higher photoinitiating activity than other thioxanthone isomers (e.g., 2-and 4-position isomers) [ n.s. allen, et.al j.oil.colour.chem.assoc.1987, 70 (11): 332 ].

It is obvious to the skilled practitioner that the 3-position substituted thioxanthone-type compounds are not used because the existing literature methods for preparing thioxanthone-type compounds disclose that electrophilic aromatic ring addition and oxidative ring closure techniques typically occur in strong protic acid media using dithiosalicylic acid starting materials and alkylbenzenes, whereas the rules of chemical selectivity for the positioning of the alkyl group in electrophilic aromatic rings dictate that only the 2-and associated 4-position thioxanthone isomers can be produced, and that 3-position substituted thioxanthone isomers cannot be produced therefrom; the synthesis of the latter and the exploration of unknown properties thereof are among the important issues that are desired but not yet solved by the skilled practitioner.

[ summary of the invention ]

The application realizes the preparation of the 3-substituted thioxanthone compound shown in the general formula (I) for the first time, and simultaneously discovers that the compound is a photosensitizer and photoinitiator compound with excellent performance. Definition of R₀Is a compound having 1 to 24 carbon atoms (denoted as C)¹-C²⁴) Branched or straight chain or cyclic alkane or substituted or unsubstituted (hetero) arene group, R in the 3-position of the thioxanthone ring system₁The radicals being OH, SH, halogen atoms, R₀，OR₀，SR₀，NHR₀Or N (R)₀)₂；R₂-R₈The radical values being, independently of one another, R₁Or hydrogen;

an exemplary, but non-limiting, structure of a compound conforming to the definition of formula (I) is as follows:

one of the processes for the preparation of the compounds of formula (I) is disclosed below, which involves acyl halogenation (from A to B), Friedel-crafts acylation (B and C react to form D), oxidation (from D to E), and cyclization in four steps to produce the desired product (I). Due to R₁Electron-donating Effect of the group, during which the acylation of the key intermediate compound D is accurately located at R₁Para position of the group, the product thus exhibiting a 3-position R₁Novel compound structures with precisely substituted groups.

Wherein R is hydrogen, C¹-C²⁴A linear or branched or cyclic alkyl group, or a substituted or unsubstituted aryl group; x and Y are independently of each other chlorine or bromine; the acid halogenating agent is phosphorus trihalide (PX)₃) Thionyl chloride, chlorine, oxalyl chloride, or in the form of Q-CX₃Trihalide of (reaction formula RCO)₂H+Q-CX₃(o) X + Q-C (o) X + HX), wherein Q is C¹-C¹⁶An alkyl or aryl group; the oxidant is chlorine, thionyl chloride, sulphuryl chloride, metal halide salt.

The second process for the preparation of the compounds of formula (I) is disclosed below, which involves acyl halogenation (from F to G), Friedel-crafts acylation (G and C react to form E), oxidation (from E to H), and cyclization in four steps to produce the target product (I). During the process, the acylation of the same key intermediate compound E is accurately positioned at R₁Para position of the group, the product thus exhibiting a 3-position R₁Novel compound structures with precisely substituted groups.

Wherein T is R or C (O) R; acyl halogenation testThe agent being phosphorus trihalide, thionyl chloride, chlorine, or in the form of Q-CX₃The trihalide of (a); the oxidant is chlorine, thionyl chloride, sulphuryl chloride, metal halide salt.

A third process for the preparation of compounds of formula (I) is disclosed below, which involves Friedel-crafts acylation (L and M react to form N), oxidation (from N to P), and cyclization in four steps to produce the desired product (I). In the process, because the raw material of the para-position substituted acyl halide L is used in advance, the reaction product naturally presents 3-position R₁Novel compound structures with precisely substituted groups.

Wherein R' is as defined for R; y is chlorine;

the oxidant is chlorine, thionyl chloride, sulphuryl chloride, metal halide salt.

The reaction solvent is selected from substituted or unsubstituted aromatic hydrocarbon containing 1-24 carbon atoms, straight-chain or branched-chain aliphatic hydrocarbon, (sulfoxide), amide, ether, ester, ketone, nitrile, carboxylic acid, water, amine, ionic liquid, supercritical carbon dioxide, or a mixed solvent consisting of any two or more of the above solvents; preferred solvents are dimethyl sulfoxide, dimethyl sulfone, benzyl sulfoxide, benzyl sulfone, cyclobutane sulfoxide, sulfolane, trichlorosilane, dichloromethane, dichloroethane, chloroform, carbon tetrachloride, benzene, toluene, xylene, trimethylbenzene, tetramethylbenzene, acetonitrile, ethylbenzene, diethylbenzene, chlorobenzene, dichlorobenzene, anisole, nitrobenzene, heptane, hexane, petroleum ether, dioxane, tetrahydrofuran, methyl tert-butyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, propylene glycol methyl ether acetate, triethylamine, tributylamine, dimethyl isopropylamine, pyridine, N, N-tetramethylethylenediamine, N-alkylmorpholine, N-alkylpyrrole, N, N-dimethylformamide, formylmorpholine, N, N-diethylformamide, N-methylpyrrolidone, or a mixture of any two or more of these solvents. The reaction can also be carried out with little or no conventional "solvent" and with solid phase heating and/or grinding of the starting materials and/or with promotion by ultrasound and/or microwave irradiation.

The reaction temperature involved in the process is selected from-70 ℃ to 200 ℃, preferably from-30 ℃ to 180 ℃, and more preferably from-20 ℃ to 150 ℃. The "pressure" of the reaction involved in the process is selected from between 0.001 and 200 atm, preferably from between 0.1 and 100 atm, more preferably from between 0.1 and 20 atm.

The disclosed 3-substituted thioxanthone compounds of the present invention have been found in practice to be excellent performance photosensitizers and photoinitiators.

We disclose a new material formula system for radiation curing, which is characterized in that:

(3) at least one photoinitiator disclosed by the general formula (I) of the invention or a mixture thereof;

(4) contains at least one ethylenically (C ═ C) unsaturated compound (monomer or resin).

Preferably, the "at least one of the photoinitiators disclosed herein or mixtures thereof" is included in the formulation in an amount of from 0.001 to 50% by mass, more preferably from 0.01 to 20% by mass.

Preferably, the formulation contains other photoinitiator species known from the literature.

The "photoinitiator substances known in the literature" are any one of the following photoinitiator compounds or a compounded mixture of any two or more of the following photoinitiator compounds: included are photoinitiator substances of the hydroxyketone type (Hydroxyketones), aminoketone type (Aminoketones), phosphonyl type (Acylphosphine Oxides), Oxime ester type (Oxime Esters), benzophenone type (Benzophenones), benzoylformate type (phenylglyoyles), thioxanthone type (Thioxanthones), onium salt type cationic photoinitiators (sulfoninums or iodonium or Photo-Acid Generators, so-called PAGs), or dyes as substantive photosensitizers (Dye Sensitizers). Examples of photoinitiators are Darocur 1173, Irgacure 184, API-180 (Shenzhen, Inc. of technical holdstocks, Inc.), API-307 (Shenzhen, Inc. of technical holdstocks, Inc.), API-308 (Shenzhen, Inc. of technical holdstocks, Inc.), API-1206 (Shenzhen, product of technical holdstocks, Inc.), API-1207 (Shenzhen, product of technical holdstocks, Inc., Irgacure 2959, Irgacure MBF, Irgacure 127, Irgacure 651, Esacure KIP-150, Esacure KIP-160, Esacure KIP-1001, Esacure 01, Irgacure 907, Irgacure 500, Irgacure 2200, Irgacure 2022, Irgacure 4500, Irgacure 369, Irgacure 379, Irgacure 819, Irgacure TPO, Irgacure TMP, Irgacure 754, Irgacure Xcure 19, Irgacure Xcure 19, Irgacure 19, Irgacure IRgacure, Irgacure 19, Irgacure or Irgacure 19, irgacure OXE-03, Irgacure OXE-03, Tronly 304 (Changzhou powerful new electronic materials Co., Ltd.), Tronly 305 (Changzhou powerful new electronic materials Co., Ltd.), Irgacure 250, ADEKA NCI-831 (Idiaceae, Japan), ADEKA N-1414 (Idiaceae, Japan), Irgacure 290, Irgacure 270, and coumarin-type dye photosensitizers, etc., which may also be compounded with a corresponding Co-initiator (Co-initiator), such as an active amine, and/or a hydrosilane-based active hydrogen donor-type Co-initiator.

The ethylenically (C ═ C) unsaturated compound (monomer) is any ethylenically polymerizable monomer, including but not limited to (meth) acrylates, acrolein, olefins, conjugated dienes, styrene, maleic anhydride, fumaric anhydride, vinyl acetate, vinyl pyrrolidone, vinyl imidazole, (meth) acrylic acid derivatives such as (meth) acrylamide, vinyl halides, vinylidene halides, and the like. The ethylenically (C ═ C) unsaturated compound (resin) is any ethylenically-containing prepolymer and oligomer, including but not limited to (meth) acryl-functional (meth) acrylic copolymers, urethane (meth) acrylates, polyester (meth) acrylates, unsaturated polyesters, polyether (meth) acrylates, silicone (meth) acrylates, epoxy (meth) acrylates, and the like, as well as water-soluble or water-dispersible analogs of the foregoing.

The functional additives are suitable various types of additives, and known to those skilled in the art are various types of additives including, but not limited to, polymerization inhibitors, active amine co-initiators, leveling agents, antifoaming agents, anti-sagging agents, thickeners, tackifiers, dispersants, antistatic agents, solubilizers, diluents, water or organic solvents, antibacterial agents, flame retardants, inorganic or organic fillers (e.g., nano alumina, silica, calcium carbonate, barium sulfate, etc.) and/or colorants (e.g., pigments or dyes, etc.), ultraviolet absorbers or/and light stabilizers to enhance weatherability of coating inks, and suitable aqueous dispersions or water-soluble products of the above components.

The novel radiation curing material formula system disclosed by the invention comprises a photo-curing coating or ink material, and has very wide application value in downstream markets such as spraying, rolling, curtain coating, wiping, dip-coating and the like and/or construction processes (such as putty, base coating, coloring, middle coating, top coating and the like) in cooperation with various construction modes, PCB (printed circuit board) ink, Laser Direct Imaging (LDI) ink, printing and packaging ink, wood furniture, plastic products, printing and packaging, ink-jet printing, electronic consumer goods, interior and exterior decorations of motor vehicles, pipeline profiles, industrial terraces, building curtain walls, 3D (three-dimensional) printing additive manufacturing, ships or container bodies and the like.

Exemplary, but non-limiting, applications of particular value are, for example, the use of such coatings or inks for the preparation of pigmented and unpigmented paints and varnishes, powder coatings, PCB inks, LDI inks, printing plates, adhesives, pressure-sensitive adhesives, dental compositions, gel coats, photoresists for electronics, electrographic resists, etch resists, both liquid and dry films, solder resists, resists for the manufacture of color filters for various display applications, resists for the manufacture of structures in the manufacturing process of plasma display panels, electroluminescent displays and LCDs, for LCDs, holographic data storage, compositions for encapsulating electronic components, for the manufacture of magnetic recording materials, micromechanical parts, waveguides, optical switches, forge masks, etch masks, color proofing systems, glass fiber cable coatings, screen printing stencils, for the production of three-dimensional objects by means of stereolithography, as image recording materials for holographic recording, microelectronic circuits, decolorizing materials for image recording materials, for image recording materials using microcapsules, as photoresist materials for UV and visible laser direct imaging systems, as photoresist materials for forming dielectric layers in sequentially built layers of printed circuit boards; in particular, the photopolymerizable compositions described above are used for the preparation of pigmented and unpigmented paints and varnishes, powder coatings, printing inks (e.g. screen printing inks, inks for offset, flexo or inkjet printing), printing plates, adhesives, sealings, potting components, dental compositions, foams, moulding compounds, composite material compositions, glass fibre cable coatings, screen printing stencils for the production of three-dimensional objects by means of stereolithography, and as image recording materials, photoresist compositions, decolorizing materials for image recording materials, image recording materials using microcapsules.

In the examples we will further illustrate.

[ detailed description ] embodiments

Example (b): 3-isopropyl-7-methyl-thioxanthone

5 g of 4-methylthiophenol was weighed into a 100 ml single-neck flask, and after 20 ml of ethanol was added to dissolve it, 0.23 g of NaOH and 3.4 ml of methyl iodide were added. After stirring at room temperature for 3 hours TLC monitored the end of the consumption of starting material. After the solvent was spin-dried, 100 ml of 1M NaOH solution and 100 ml of ethyl acetate were added, shaken, and the organic phase was spin-dried by liquid separation to obtain a pale yellow solid with a yield of 95%.¹H NMR(400MHz，CDCl₃)：δ＝7.25(d，J＝7.9Hz，2H)，7.16(d，J＝7.9，2H)，2.51(s，3H)，2.38(s，3H)。

5 g of 4-isopropylbenzoic acid was weighed into a 100 ml flask, 20 ml of dichloroethane was added and dissolved, 4.3 ml of thionyl chloride was added and stirred at room temperature for 6 hours, and then the end of the consumption of the raw material was monitored by TLC. The solvent was evaporated under reduced pressure to give a colorless oily liquid with a yield of 98%.

Under the protection of nitrogen, 8 g of 4-isopropylbenzoyl chloride is added into a 100 ml flask, 20 ml of dichloroethane is added and stirred to be dissolved, and 0.64 g of anhydrous AlCl is added at 0 DEG C₃After 30 minutes of reaction, 4-methyl-thioanisole is added to react for 6 hours at room temperature, the reaction is quenched by 5% hydrochloric acid and then extracted by dichloroethane for three times, organic phases are combined, and yellow oily liquid is obtained by column chromatography with the yield of 75%.¹H NMR(400MHz，CDCl₃)：δ＝7.73(d，J＝4.0Hz，2H)，7.34-7.24(m，4H)，7.16(br s，1H)，3.01-2.93(m，1H)，2.38(s，3H)，2.34(s，3H)，1.28(d，J＝3.2Hz，6H)。

6 g of the acylated product was added to a 100 ml three-neck flask, 30 ml of dichloroethane was added to dissolve the product, and then sulfonyl chloride was slowly added dropwise thereto, followed by stirring at room temperature for 3 hours, followed by TLC to monitor disappearance of the starting material, and the solvent was then dried by purging with nitrogen gas, resulting in a yield of 95%.

The intermediate was dissolved in 30 ml of dichloromethane with stirring, and 3.5 g of anhydrous ZnCl2 powder was added under ice-bath to react for 4 hours with stirring. After the solvent was spin dried, 100 ml of 15% HCl and 100 ml of dichloromethane were added, the organic phase was spin dried by liquid separation and column chromatography was performed to obtain a white solid with a yield of 74%.¹H NMR(400MHz，CDCl₃)：δ＝8.46(d，J＝20Hz，2H)，7.53-7.41(m，4H)，3.10-3.02(m，1H)，2.49(s，3H)，1.33(d，J＝3.8Hz，6H)。

Example (b): 3-isopropyl-thioxanthones

Weighing 20 g of 2, 2-dithiosalicylic acid, adding into a 250 ml single-neck flask, adding 150 ml of glacial acetic acid for dissolution, adding 13.5 g of zinc powder, refluxing and stirring at 120 ℃ overnight, adding 100 ml of 1M HCl solution into the reaction solution after TLC detection of raw material consumption, adding 100 ml of ethyl acetate, stirring for 2 hours, separating, and spin-drying the organic phase to obtain a light yellow solid, wherein the yield is quantitative.

20 g of thiosalicylic acid is added into a 250 ml single-neck flask, 100 ml of methanol is added to dissolve the thiosalicylic acid, 12.5 g of NaOH is added to the mixture, the mixture is stirred for 30 minutes, and 8.5 ml of methyl iodide is added dropwise. Stirring at room temperature for 6 hours, and detecting the completion of the raw material reaction by TLC. After the solvent was spin-dried, 100 ml of 1M HCl solution was added, 100 ml of ethyl acetate was added, the reaction was stirred for 2h, and the organic phase was spin-dried by liquid separation to obtain a white solid with a yield of 87%.¹H NMR(400MHz，CDCl₃)：δ＝8.15(dd，J＝7.9，1.2Hz，1H)，7.55-7.51(m，1H)，7.30(d，J＝7.9Hz，1H)，7.20(t，J＝3.8Hz，1H)，2.48(s，3H)。

Under the protection of nitrogen, 10 g of the compound and 100 ml of dichloromethane are sequentially added into a 250 ml flask, stirred and dissolved, 40 ml of oxalyl chloride is added at normal temperature, stirred and reacted for 6 hours, and the reaction is completed, and the solvent is dried by spinning to obtain a light yellow solid product.

2 g of o-methylmercaptosalicyl chloride freshly prepared by the action of thionyl chloride as described above were added to a 100 ml one-neck flask, dissolved by adding 10 ml of dichloromethane, and then 1.9 g of anhydrous A1C1 were added₃After stirring for 30 minutes, 1.24 ml of cumene was added dropwise. After stirring in ice bath for 6 hours, TLC detection shows that the material is completely consumed. After the solvent was spin dried, 100 ml of 1M HCl (1mol/L) solution was added, 100 ml of ethyl acetate was added and stirred for 2 hours, and the organic phase was spin dried by liquid separation to obtain a white solid with a yield of 92%.¹H NMR(400MHz，CDCl₃)：δ＝7.73(d，J＝3.9，2H)，7.47-7.28(m，5H)，7.23-7.19(m，1H)，3.00-2.94(m，1H)，2.42(s，3H)，1.27(d，J＝3.4，6H)。

Placing 2 g of the compound in a 100 ml flask, adding 30 ml of dichloromethane to dissolve the compound, then dropwise adding 2 equivalents of sulfonyl chloride, stirring at room temperature for 6 hours, monitoring the reaction by TLC, and performing spin-drying on the solvent to obtain a crude product with the yield of 95%.

Into a 100 ml single-neck flask N₂Adding 2 g of the raw materials under protection, adding 30 ml of dichloromethane, stirring and dissolving, and adding 3.5 g of anhydrous ZnCl under ice bath₂Stirring the mixtureThe reaction was allowed to proceed for 6 hours and TLC monitored for complete consumption of starting material. After the solvent is dried by spinning, 100 ml of 5% HCl solution is added, 100 ml of dichloromethane is added for stirring for 30 minutes, the organic phase is dried by spinning through liquid separation to obtain a light yellow solid, and a white solid product is obtained through column chromatography, wherein the yield is 68%.¹H NMR(400MHz，CDCl₃)：δ＝8.63(d，J＝7.8，1H)，8.50(s，1H)，7.63-7.45(m，5H)，3.11-3.02(m，1H)，1.33(d，J＝7.2，6H)。

Example (b): 1, 3-diethyl-thioxanthones

Weighing 12.6 g of 2, 2-dithio salicylic acid and 30 ml of thionyl chloride, mixing, refluxing and reacting for 3 hours, directly diluting the concentrated acyl chloride crude product with 120 ml of dichloroethane, and sequentially adding 9 g of m-diethylbenzene and 8.5 g of anhydrous AlCl₃After stirring the reaction mixture for 6 hours, the mixture was decomposed with 150 ml of 1M HCl solution, the organic phase was filtered and concentrated, and then recrystallized from ethanol to give 7.4 g of diacylated product.

5.5 g of the diacylated product was placed in a 100 ml three-neck flask, 30 ml of dichloroethane was added to dissolve the diacylated product, and then chlorine gas was slowly introduced thereto, and the mixture was stirred at room temperature for 3 hours, and then the solvent was spin-dried by purging with nitrogen gas.

The intermediate was dissolved in 50 ml dichloromethane with stirring again and 2.7 g anhydrous AlCl was added under ice-bath₃The powder was stirred for 4 hours. After the solvent was spin-dried, 120 ml of 5% HCl and 100 ml of dichloromethane were added, the organic phase was spin-dried by liquid separation and then subjected to column chromatography to obtain 2.8 g of a pale yellow solid product.

Example (b): photopolymerization initiation Activity Properties

Samples of the ethylenically (acrylate) containing UV radiation curable material formulation system were prepared according to the following formulation (in weight percent): bisphenol a epoxy acrylate (Ebecryl 605): 20 percent; amine-modified acrylate: 12% (reactive amine resin); aminoacrylate (Ebecryl 7100): 10 percent; acryloyl morpholine: 55 percent; photoinitiator (2): 3 percent.

Evaluation of photocuring performance: the above samples were applied to cardboard to form a coating of about 20-25 microns using a UV high pressure mercury lamp (about 20 cm from the substrate) as the source of radiation and a variable speed conveyor test. The criterion for completing photopolymerization curing is that repeated nail scratching and scratching can not generate marks.

The results are as follows: when the photoinitiator is 3 percent of 3-isopropyl-7-methyl-thioxanthone, the maximum linear speed of complete photocuring is 48 m/min; when the photoinitiator is 3 percent of 3-isopropyl-thioxanthone, the maximum linear speed of complete photocuring is 45 m/min; when the photoinitiator was 3% 1, 3-diethyl-thioxanthone, the photocuring completion maximum line speed was 50 m/min. The above tests demonstrate the excellent photopolymerization initiation activity of the disclosed compounds.

Samples of the ethylenic radiation curable PCB ink material system were prepared according to the following formulation (in weight percent): in the component A, o-cresol formaldehyde epoxy acrylate oligomer: 55 percent; DBE solvent: 20 percent; photoinitiator (2): 4 percent; silicon dioxide: 1.5 percent; barium sulfate: 11.5 percent; titanium dioxide: 8 percent; in the component B, DPHA acrylate monomer: 35 percent; epoxy resin: 35 percent; DBE solvent: 20 percent; barium sulfate: 10 percent. Mixing the above materials, adding into a dispersing barrel, dispersing with a high-speed disperser, grinding with a hydraulic three-roller machine for 5 times, filtering with a filter element filter, and spray-printing the obtained ink on PCB board at 80m/min with an ink-jet printer with XAAR nozzle, wherein the linear power of the curing light source is about 200W/cm. Photoinduced activity was quantified using a Stouffer-type exposure standard 21-step gray scale.

Evaluation of photocuring performance: when the photoinitiator is Irgacure 907 of 3.5 percent and 2-ITX of 0.5 percent, the exposure gray scale is 9 grades; when the photoinitiator was Irgacure 907 at 3.5% and 3-ITX at 0.5%, the exposure gray scale was of order 10. The above tests demonstrate the higher photosensitivity performance of the disclosed compounds.

It should be emphasized that the above-described embodiments are merely illustrative and not restrictive, and that any adjustments or variations, such as reaction conditions or parameters, which may be commonly employed by a person skilled in the art based on the disclosure of this application do not depart from the gist of the present invention, and the scope of protection of this patent shall be governed by the terms of the relevant claims.

Claims

1. Novel thioxanthone compounds having 3-position substitution characteristics represented by general formula (I). Definition of R₀Is a compound having 1 to 24 carbon atoms (denoted as C)¹-C²⁴) Branched or straight chain or cyclic alkane or substituted or unsubstituted (hetero) arene group, R in the 3-position of the thioxanthone ring system₁The radicals being OH, SH, halogen atoms, R₀，OR₀，SR₀，NHR₀Or N (R)₀)₂；R₂-R₈The radical values being, independently of one another, R₁Or hydrogen;

2. a process for the preparation of compounds of formula (I) involving four steps of acyl halogenation (from A to B), Friedel-crafts acylation (B and C react to form D), oxidation (from D to E), and cyclization to produce the desired product. Wherein R is hydrogen, C¹-C²⁴A linear or branched or cyclic alkyl group, or a substituted or unsubstituted aryl group; x and Y are independently of each other C1 or Br; the acid halogenating agent is PX₃，SOCl₂，C1₂Or of the form Q-CX₃Of a trihalide of (A), Q is C¹-C¹⁶An alkyl or aryl group; the oxidant is chlorine, thionyl chloride, sulfuryl chloride, metal halide salt;

3. a process for the preparation of compounds of formula (I) involving four steps of acyl halogenation (from F to G), Friedel-crafts acylation (G and C react to form E), oxidation (from E to H), and cyclization to produce the desired product. Wherein T is R or C (O) R; y is chlorine; the acid halogenating agent is PX₃，SOCl₂，Cl₂Or of the form Q-CX₃III of (2)A halide; the oxidizing agent is chlorine, thionyl chloride, sulfuryl chloride, metal halide salt:

4. a process for the preparation of a compound of formula (I) which involves four steps of Friedel-crafts acylation (L and M react to form N), oxidation (from N to P), and cyclization to produce the desired product. Wherein R' is as defined for R; y is chlorine; the oxidant is chlorine, thionyl chloride, sulfuryl chloride, metal halide salt;

5. according to claim (I), exemplary but not limiting structures conforming to the defined compounds are as follows:

6. a novel radiation curing new material formula system is characterized in that:

(1) at least one photoinitiator disclosed by the general formula (I) of the invention or a mixture thereof;

(2) contains at least one ethylenically (C ═ C) unsaturated compound (monomer or resin).

7. According to the claims (1) and (6), the photoinitiator and radiation curing formulation system, i.e. the photocurable coating or ink material, is used in combination with various construction methods (spraying, rolling, curtain coating, wiping, dip coating, etc.) and/or construction procedures (putty, base coating, coloring, middle coating, top coating, etc.), in PCB ink, Laser Direct Imaging (LDI) ink, printing and packaging ink, wood furniture, plastic products, printing and packaging, ink-jet printing, electronic consumer goods, interior and exterior trim of motor vehicles, pipeline profiles, industrial terraces, building curtain walls, 3D printing additive manufacturing, and applications in downstream markets such as ships or container bodies.